On generalized wormhole in the Eddington inspired Born-Infeld (EiBI) gravity

TL;DR

This paper explores observable effects of a generalized wormhole solution in EiBI gravity, highlighting how the parameter κ influences tidal forces, energy conditions, and the nature of exotic matter, differing from general relativity.

Contribution

It introduces a generalized EiBI wormhole model with a new parameter κ, analyzing its effects on observables and energy conditions, extending previous GR solutions.

Findings

Non-zero κ prevents infinite tidal forces near small throats.

Energy conditions are violated in the EiBI wormhole.

Exotic matter cannot be interpreted as phantom or ghost fields.

Abstract

In this paper, we wish to investigate certain observable effects in the recently obtained wormhole solution of the EiBI theory, which generalizes the zero mass Ellis-Bronnikov wormhole of general relativity. The solutions of EiBI theory contain an extra parameter $\kappa$ having the inverse dimension of the cosmological constant $\Lambda$, and is expected to modify various general relativistic observables such as the masses of wormhole mouths, tidal forces and light deflection. A remarkable result is that a non-zero $\kappa$ could prevent the tidal forces in the geodesic orthonormal frame from becoming arbitrarily large near a small throat radius $(r_0 \sim {0})$ contrary to what happens near a small Schwarzschild horizon radius $(M \sim 0)$. The role of $\kappa$ in the flare-out and energy conditions is also analysed, which reveals that the energy conditions are violated. We show that the exotic matter in the EiBI wormhole cannot be interpreted as phantom $({\omega}=(p_{r}/ \rho)<-1)$ or ghost field ${\phi} $ of general relativity due to the fact that both $\rho$ and $p_{r}$ are negative for all $\kappa$.